Knitting head



Oct. 14, 1941 w. LARKIN 2,259,384

KNITTING HEAD Filed Nov. 12, 1940 5 Sheets-Sheet 1 I I 1L 7567i F V Z7 W. LARKIN Oct. 14, 1941.

KNITTING HEAD Filed Nov. 12, 1940 5 Sheets-Sheet 4 PetentedOet. 14, 1941 UNITED STATES" PATENT OFFICE corporation of Delaware Application November 12, 19 4o, Serial No. 365,346

25 Claims. (01. 66- -9) This invention relates to a knitting head for a circular knitting machine adapted for knitting seamless tubular ribbed fabric having a wire, a

texin'le yarn, a rubber strand, or a combination of such filaments laid-in in predetermined courses of the stitches of which the tube is composed, as disclosed, for example, in my copending application Serial No. 359,793, filed October 4, 1940.

The knitting head of the present invention is particularly adapted for knitting tubes of relatively small diameters, with the stitch wales of the fabric disposed in close lateral relation to each other to produce a compact fabric.

The needles of the knitting head are divided into two seriw, with the needles of one series alternating with the needles of the other series circumferentially of the knitting head, one of said series being adapted to produce the stitches of the inside wales of the fabric, and the other to produce the stitches of the outside wales thereof.'

The needles of each series are slidably mounted, for independent longitudinal movement, in

separate needle cylinders and the two cylinders are arranged in axial alignment with respect to each other, with an annular work slot formed between the adjacent ends of the twin-cylinders for the passage of the knitted tube into and through the interior bore of one or the other of the cylinders.

Normally, in machines employing axially aligned twin-cylinders, there are twice as many needle grooves in each cylinder as there are needles, 1. e. there is a vacant slot between each two occupied slots in each cylinder to accommodate the hook ends of the needles of the other cylinder, during movement of the needlesto clearing position in the knitting operation. In

cases where the wales of the fabric are to be formed in close lateral relation to each other, the partitions between successive needle grooves in each cylinder are necessarily thin and fragile. However, with the thinnest possible practical partitions, the needle grooves are necessarily spaced 4 a considerable distance apart laterally. This. condition places a serious limitation on the fabrics possible to produce in such machines,as the spacing of the needle grooves determines the spacing of the stitch wales, and the spacing of the stitch wales determines the circumferen compactness of the fabric. i- A One object of the present invention is to provide a novel form of needle cylinder for use in ranged in axial alignment, whereby the wales of the fabric may be produced in laterally abutting relation to each other, if desired.

Another object of the invention is to make each cylinder as a unit of annular stepped formation composed of two separable concentric parts of relatively different diameters, with the end of the inner part of smaller diameter which is adjacent the work slot extended axially beyond one end of the outer part of larger diameter: to form the grooves for the needles of that particular unit in the outer peripheral face of the outer larger part; to form clearance slots for the hook ends of the needles of the other unit in the axially extended portion of the smaller inner part; and to form the bases of the needle grooves at an angle to the axis of the units so that hook ends of the needles of one unit, when moved to clearing position in the grooves of the larger part of that unit, will enter the clearance recesses in the smaller part of the other unit.

Another object'of the invention is to provide a novel form of tubular mandrel within the bore of one of the cylinder units to extend from that unit into the bore of the other of the axially aligned twin-units, across the work slot formed between the adjacent ends of the inner parts of said units, to form the inlay wire, etc., at the work slot, into convolutions of predetermined diameters less than the diameters of the internal bores of the respective cylinder units, for free movement through the bore of one of the cylin- I der units with the knitted tube.

Another object of the invention, in forming each cylinder unit of two concentric parts, is to provide as thin an annular edge as possible at the work slot, in order to effect the knitting on a circle of lesser diameter than the bore of the head forming the subject matter of the present invention will be fully disclosed hereinafter, reference being bad to the accompanying drawings, of which: i

Fig. 1 is a diagrammatic side elevation of a knitting machines employing twin-cylinders ar- '55 circular knittin machine of the general type to which the knittii. g head of the present invention is particularly adaptable;

Fig. 2 is an enlarged longitudinal sectional elevation of the knitting head; I

Figs. 3 and 4 are sectional elevations, on a still further enlarged scale, illustrating the extended movement of the needles beyond the needle grooves-of the outer part of one cylinder unit into the clearance slots of the inner part of the other of the twin-units;

Fig. 5 is a fragmentary flat development view of the outside of the two needle cylinder units, at and adjacent the work slot therebetween;

Fig. 6 is a sectional plan view taken on the line 6-6, Fig. 2, with the needles removed; I

Fig. 7 is an outside elevation of the outer part of a cylinder unit;

Fig. 8 is an outside elevation of the inner part of a cylinder unit;

' Fig. 9 is an outside view of the mandrel;

Fig. 10 illustrates a detail of the invention;

Fig. 11 is a view similar to Figs. 3 and 4 with the needles in casting position; and

Fig. 12 illustrates a modification of the invention;

As shown in Fig. 1, a machine of the type to which the lmitting head structure of the present invention is particularly adaptable, normally comprises a rigid-base member I, to which is rigidly secured a lower cylinder supporting tube 2. Axially aligned with the cylinder supporting tube 2 is a second or upper cylinder supporting tube 3. The supporting tube 3 is rigidly mounted in a super-structure 4. The base member and superstructure 4 are rigidly supportedlby a common framework 5.

Rotatably mounted in or on the base for rotation about the lower support tube 2, is a cam ring andyam cone supporting and driving ring 5. The supporting and driving ring 6 is driven by the usual gearing, common to this type of machine, from any suitable source of power. -Rigidly secured in the driving ring 6, and extending vertically therefrom, is a plurality of cam ring supporting posts I, I, the upper ends of which may, if desired, be secured in a. collar 8 freely rotatable on and about the upper cylinder support 3 adjacent the super-structure 4.

As shown in Fig. 2, identical lower and upper cylinder units A and A respectively, are secured to the adjacent axially spaced ends of the lower and upper cylinder supporting tubes 2 and 3, respectively. The units A and A are spaced apart axially to form an annular work slot a: therebetween. As the cylinder units A and A are identical in structure, detailed description of one will suflice for both. v

As shown in Figs. 2, 7 and 8, each cylinder unit comprises an outer part In and an inner part II concentric to the outer part iii. The outer part II] is in the form of a hollow cylinder or sleeve and is provided with an annular shoulder l2. adapted to rest against the end |3 of the supporting tube 2 or 3, as the case may bejsaid shoulder being provided by reducing theone end of the cylinder in diameter to form a neck l4 adapted to fit snugly into the supporting tube 2 or 3. Any suitable means may be provided for securing the outer cylinder element ill to the supporting tube as, for example, by thescrews l5 shown in Fig. 2.

As shown in Fig. 2, the outer cylinder element I 0 is provided in its peripheral surface with a plurality of needle grooves l6 which extend longitudinally of said element, in planes radiating from the axis of said element. The grooves l6, l6 are spaced apart circumferentially of the element to form partitions l1, l1 therebetween.

Also as shown in Fig.2, the base surfaces IQ of the needle grooves l6 are disposed at an angle with respect to the axis of the element In and converge toward the work slot :1: formed by and between the adjacent ends of the inner parts II, II of the units A and A respectively.

The end of the element l0, opposite to that on which the neck I4 is formed, is provided with an annular groove l9 for reception of a resilient annular needle retainer 20. Between the ,annular groove I9 and the end surface 2| the element I0 is provided with a narrow annular flange 22 through which the needle grooves 6, l6 extend. Adjacent theopposite side of the annular groove IS the element I0 is circumferentially beveled, asindicated at 23.

The inner element ll of each cylinder unit is composed of a relatively thin tube 25, which is adapted to fit snugly'within the interior bore 26 of the element l0. One end of the tube 25 is provided with an annular flange 21, which is adapted to bear against the end surface 28 of the neck l4 of the element I0 and to be secured thereto by means of screws or bolts 29, to prevent relative circular or axial movement of the inner element II with respect to the outer element Ill.

The opposite end of the inner element II is circumferentially beveled, as indicated at 30, on an angle corresponding to the angle of the bases l8 of the needle grooves iii in the outerelement Ill. The beveled face 30 of the inner part I I forms a continuation of the bearing surfaces provided by the groove bases l8, for supporting theneedles during independent longitudinal movements thereof during the knitting operation.

The second or beveled end 30 of the inner element II is provided with a plurality of recesses or slots 3| which are formed therein and extend longitudinally thereof, parallel to the axis of the element II, in circumferentially spaced relation around said element l I.

Immediately adjacent the end surface 32 of the inlongitudinal alignment with the needle grooves It in the outer element l0 of the other unit, and the base surfaces 35 of the end grooves 34 of the inner element of each unit lie in alignment with the base surfaces l8 of the needle grooves IS in the outer element ll] of the other unit, as clearly shown in Figs, 2, 3 and 4, to receive the hook ends 36 of the. needles 31 when said needles are moved to clearing position across the work slot 2:.

As shown in Figs. 2, 3 and 4, the axially spaced end surfaces 32, 32 of the inner elements ll of the cylinder units A and A respectively, form and define the annular work slot ac.

Also as shown in Figs. 2, 3 and 4, the ends of the inner elements II, II, in which the needlereceiving slots or openings 3| and grooves 34 are formed, extend a substantial distance axially beyond the end surfaces 2|, 2| of the outer elements l0, ID with which the inner elements II, II are respectively associated. When a needle 31 is extended to clearing position, as shown in Figs. 3and 4, with the back edge 36 of the shank of the needle bearing against the base surface l8 1 of needle groove |6 in outer element III of the unit with which the needle is primarily associated and against the cir'cumferentially beveled surface 36 of the inner element ll of the same unit, the back edge 38 of the extended needle also bears against the base surface 35 of the needle-receiving groove 34 in the annular portion 33 of the With the above noted construction, each needle cylinder element I is provided with only the same number of needle grooves as there'are needles in the series associated with the respective cylinder elements, as ther'e is no necessity for stance, for each revolution of the knitting cams forming intermediate grooves in these needle cylinder elements to receive the hook ends of the needles of the other series, consequently the partitions |1 between successive needle grooves l6,

cally opposite sides of the outer elements III of the two units A, A the needlesare operated in paths which convergeinwardly toward the work slot :r, whereby the actual formation of the fabing ring 55. The ring 55, in turn, is mounted within a ring 56 carried by or formed integral with the supporting posts'1, 1. The ring 55 is provided with radial lugs 51, 51 (Fig. 6) which overlie the ring 56 and are secured thereto by bolts or screws 56, 58. v

The posts 5|, 5| are formed with loose ends 45. 45 which are adapted to be secured to the posts 5|, 5| respectively by bolts or screws 53, 53 to gripthe flanges 46 of the adjusting rings 44 tightly after the rings 44, 44 have been rotated to adjust the cam rings 42, 42 so that the cam slots ,59, ,59, of the cams 46, 49, in which the butts 39, 39 of the needles 31, 31operate, will operate the needles in proper relation to the work slot 0:. v a

The ring 55 supports diametrically opposite yarn guides or feeds 69, 66 for feeding a pair of yams under'the hooks 36 of the needles 31 to form two courses of stitches, in the present in- 4||, relative to the flxed needle cylinder units A, A

The ring 55 also carries yam tensioning discs 6|, 6| adjacent the guides 60, 60, with tension springs 62, 62 encircling-the posts 5|, 5|. Adjusting collars 63, 63 on the posts 5|, 5| regulate the tension applied to the knitting yarn by the A tubular mandrel 65 (Fig.9) is mounted withv in one of the inner parts ll of one ofthe needle cylinder units A or A as the case may be. In the present instance, the mandrel 65 is mounted within the upper unit A, and is provided with an annular flange 66 which,rests on top of the annular flange 21'of the upper innerelement ric is effected on a circle of minimum diameter, I,

inside the bore of the inner element ll of the cylinder unit A, in the present instance, as shown in Fig, 11. I

As a result of the angularity of the base surfaces l9 of the needle grooves I6, the ends of I the needles 31, opposite to those on which the hooks 36 are formed andwhich carry the operating butts 39 (Fig. 2) at diametrically opposite .points in each needle cylinder element II) are in divergent relationto each other, which causes the butts 39 of the needles 31 to lie' on a circle of relatively larger diameter than the circle occupied by the hooks 360i the needles, conse- -quently providing greater lateral spacing between adjacent butts for freer operation of said butts by the operating cams of the machine.

The flange 66 is secured to the flange 21 in any suitable manner, as by screws 61.

The mandrel 65 is provided with an annular boss 66 or the annular'solid portion 33 of the encircling tube element M, if desired, may be downwardly into the upper end of the lower iniay:'

tube past the work slot to receive an wire, etc., B which is fed into the work slot :2: against and between the stitches 1 of the outside wales of the fabric F hanging on the medies ofthe lower unit A andthe stitches z of the inside wales hanging on the needles of the upper unit A when the needles are in stitch internally threaded adjusting ring 44. Each adtwo posts 5|, 5| are rigidly securedin a support- 76 The wire, etc., B is fed into the work slot at by afeeding or guiding eye 1| carried by the ring between the two-yam feeds 60, (Fig.

6) to place an inlay element B'in alternate,

courses, in' the present instance, although an inlay feeder 1| may be provided for each yam feed 60 if desired, or for any number of yarn feeds .if and when the machine employs 'four,

six or any number of yarn feeds greater than the two disclosed in the present case. The guide 1| draws-the inlay flrmly about the cylindrical end 160i the mandrel within the work slot 5: to form the inlay into convolutions having an inner diameter substantially equal to the outer diameter of the lower cylindrical end 18 of the mandrel, and in order to relieve the resistance to the movement of the knitted tube F downwardly into the lower element Ii, as created by the inlay B being drawn firmly about the mandrel, the portion of the mandrel immediately adjacent the extreme lower end thereof is slightly beveled or tapered, as indicated at 12 (Fig. 9).

In the case of a spring wire being used for the inlay element B, as disclosed in the above noted copending application, the wire convolutions after flexing of the wire around the mandrel, have a tendency to unwind, due to the inherent resiliency of the wire, and twist the fabric tube about its axis, in a direction opposite to the direction in which the wire guidetravels around the mandrel. This twists the wales from a parinner tube ll of the knitting head.

The holding device 15, as shown in Fig. 1, includes a plurality of endless belts or grooved wheels 16, IE on shafts I8, 18 which are geared together at 19, and driven at a peripheral speed equal to therate of production of the fabric tube F. a

coating substance may be applied by the apparatus shown in Fig. 12, wherein a saucer-like element82 is secured to the lower end of the pipe 8| in place of the spray head 80. The outer edge of the saucer 82 is substantially the same diameter as the interior of the tube, or slightly smaller, and is provided with small circumferentially spaced notches 83 through which the viscous coating material flows evenly and runs together below the saucer 82 to form a circumferentially and longitudinally continuous coating on the inside of the tube, while the circumferential edge of the saucer intermediate the notches 83, engages the inside of the tube and centers the saucer therein to provide a coating of uniform thickness.

I claim:

l. A knitting head comprising twin needle cylinder units aligned and spaced axially with an annular work slot therebetween, each unit having a circular concentric step formation including a cylindrical portion of one diameter at and adjacent said work slot, and a cylindrical portion of larger diameter spaced from said work slot, said larger portion having longitudinal needle grooves formed in its outer peripheral surface, and said smaller portion having longitudinal needle recesses formed in its outer peripheral surface between said work slot and said relativeo ly spaced larger portion, with said recesses al- As soon as the fabric tube F is discharged from ternating with said grooves circumferentially of said knitting head.

2. A knitting head comprising twin needle cylinder units aligned and spaced axially with an annular work slot therebetween, each unit having a circular concentric stepped formation including a cylindrical portion of one diameter at and adjacent said work slot, and a cylindrical portion of larger diameter spaced from said work slot, said larger portion having longitudinal needle grooves formed in its outer peripheral surface with the base surfaces of said grooves disposed at angles to the axis of said head and converging towardsaid axis and said work slot,

These two conditions combined produce a fabric tube of maximum compactness.

In some cases, the tube in its compact form F supra, is sprayed or otherwise treated with a substance, such asliquid latex, to fill the interstices of the fabric. In other instances, the fabric tube F is sprayed internally as it is being knit, i. e., shortly after a course of stitches passes below the free end of the mandrel,it comes into a filling or impregnating zone within the lower inner tube ll. The zone of impregnation or filling is-created therewith on the end of a pipe. 8| which is'hung and said smaller portion having longitudinal needle recesses formed in its outer peripheral surface between said work slot and said relatively spaced larger portion, with said recesses alternating with said grooves circumferentially of said knitting. head.

3. A knitting head comprising twin needle cylinder units. alignedv and spaced axially-with an from a disc 82 seated on top of the annular flange "of the uppertube element II.

It will be understood that when the fabric tube" F is sprayed while it is being knit, the wales are straight, i, e., parallel to the axis of the fabric annular: work slot therebetween; each unit having a circular concentric stepped formation including a cylindrical portion of one diameter at and adjacent said work slot, and a cylindrical portion of larger diameter spaced from said work slot, said larger portion having longitudinal needle-recesses formed in its outer peripheral surface with the base surfaces of said grooves disposed at angles to the axis of saidhead and con-.

verging toward said axis and said work slot,

' and said smaller portion having longitudinal needle recesses formed it its outer peripheral surface between said work slot and said relatively spaced. larger portion, with said recesses alternating with said grooves circumferentially of said ing greater space to receive the impregnating or knitting head, said recesses in each unit having of the tube F, a more viscous liquid orsemiliquid ing a circular concentric stepped formation ining said mandrel at one of its ends within said knitting head to one side of said work slot with I the oppositeend of said mandrel extending across and terminating beyond the opposite side of said work slot.

8. A knitting head comprising twin needle cylinder units aligned and spaced axially-with an annular work slot therebetween, each unit havinga circular concentric stepped formation inbetween said work slot and said relatively spaced larger portion, with said recesses alternating with said grooves circumferentially of said knitting head, said recesses in each unit having base surfaces in angular alignment respectively with the base surfaces of the needle grooves in the I other of said twin units and the ends of said smaller portions 'acent said work slot having beveled needle be surfaces in angular alignment respectively with the bases of the needle grooves in the respectively associated larger portions of the intermediate the recesses in the smaller portions of the units.

5. A knitting head comprising twin needle cylinder units aligned and spaced axially with an annular work slot therebetween, each unit having a circular concentric stepped formation including a cylindrical portion of one diameter at and adjacent said work slot, and a cylindrical portion of larger diameter spaced from said work slot, said larger portion having longitudinal needle grooves formed in its outer peripheral surface, and said smaller portion having longitudinal needle recesses formed in its outer peripheral surface between said work slot and said relatively spaced larger portion, with said recesses alternating with said grooves circumferentially of said knitting head,and an inlay controlling mandrel within, said knitting head in the 1 plane of said work slot.

6. A knitting head comprising twin needle cylinder units aligned and spaced axially with an annular work slot therebetween; each unit having a circular concentric stepped formation including a cylindrical portion of one diameter at and adjacent said work slot, and a-cylindrical portion of larger diameter spaced from said work slot,

cluding a cylindrical portion of one diameter at' and adjacent said work slot, and'a cylindrical portion of larger diameter spaced from said work slot, said larger portion having longitudinal needle grooves formed in its outer peripheral surface, and said smaller portion having longi-v tudinalneedle recesses formed in its outer p' ripheral surface between said work slot and said relatively spaced larger portion, with said recesses alternating with saidgrooves circumferentially of said knitting head; an inlay controlling mandrel within said knitting head in the i plane of said work slot, means for supporting said mandrel at one of its ends within said knitting head to one side of said'work slot with the opposite end of said mandrel extending across and terminating beyond the oppositeside of said work slot, and means extending axially of said knitting head through and beyondsaid opposite end of the mandrel for .applying-a coating :ubstance to the interior wall of the knitted ube.

9. A knitting head comprising twin needle cylinder units aligned and spaced axially with an annular work slot therebetween, each unit having a circular concentric stepped formation in- ,cluding a cylindrical portion of one diameter at and adjacent said workslot, and a cylindrical portion of larger diameter spaced from said said larger portion having longitudinal needle grooves formed in its outer peripheral surface, and said smaller portion having longitudinal needle recesses formedin its outer peripheral I surface between said work slotand said relatively spaced larger portion, with said recesses alternating with said groovesscircumferentiallyof said knitting head, and an inlay controlling mandrel within said knitting head in the plane of said work slot and tapering off from said work slot to a free end of said mandrel.

'7. A knitting head comprising twin needle cylinder units aligned and space axially with an annular work slot therebetween, each unit having a circular concentric stepped formation including a cylindrical portion of one diameter at and adjacent said work slot, and a cylindrical portion of larger diameter spaced from said surface, and said smaller portion having longitudinal needles recesses formed in its outer peripheral surface between-said work slot and said relatively spaced larger portion, with said recesses alternating withsaid grooves circumfer entially of said knitting head, an inlay controlwork slot, said larger portion having longitudinal needle grooves formed in its outer peripheral surface, and said smaller portion having longitudinal needle recesses formed in its outer peripheral surface between said work slot and said relatively spaced larger portion, with said recesses alternating with said grooves circumferentially of said knitting head, an inlay controlling mandrel within said knitting head in the plane of said work slot, means rotatable about said knitting head to lay an inlay element in said work slot against the stitches of the fabric tube being knitted, means located axially beyond said mandrel 'for gripping said fabric tube to prevent twisting thereof, andmeans, for operating said, holding means at a. linear sp'eed com inensurate with the speed of production of said fabric tube by said'kni-tting head.

10. A needle cylinder unit of circular concentrically stepped formation including a cylindrical portion of one diameter having needle grooves in its outer peripheral surface, and a cylindrical portion of lesser diameter projecting axially beyond one end of the first said portion with needle receiving recesses in its outer peling mandrel within said knitting head in the a plane of said work slot, and means for supportwork slot, said larger portion having longitudinal v needle grooves formed in its outer peripheral ripheralsurface in alternating relation to said grooves circumferentially of said unit.

11. A needle cylinder unit of oilular conce trically stepped formation including a cylindrical portion of one diameter having needle grooves in its outer peripheral surface, and a cylindrical portion of lesser diameter'project'ing axially beyond one end of the first said portion with needle receiving recesses in its outer peripheral surface in alternating'relation to said grooves circumferentially of said unit, with the bases of said grooves disposed at a predeterdiameter portion. I

12. A needle cylinder unit of circular concenmined angle to the axis of said unit and converging toward the exposed end of saidsmaller trically steppedformation including a cylindrical portion of one diameter having needle grooves in its outer peripheral surface, and a cylindrical portion of lesser diameter projecting axially beyond one end of the first said portion with needle receiving recesses in its outer pe- .ripheral surface in alternating relation to said I grooves circumferentially of said unit, with the bases of said grooves disposed at a predetermined angle to the axis of said unit and converging toward the exposed end of said smaller diameter portion, and a circumferential bevel on the outer peripheral surface of said smaller diameter portion adjacent said exposed endthereof, the angle of said bevel beinggcoextensive with the angle of said groove base surfaces.

13. A needle cylinder unit of circular concen trically stepped formation including a cylindrical portion of one diameter having needle grooves in its outer peripheral surface, and a cylindrical portion of lesser diameter projecting axially beyond one end of the first said portion with needle receiving recesses in its outer peripheral surface in alternating relation to said grooves circumferentially of said unit, with the bases of said grooves disposed at a .predetermined angle to the axis of said unit and converging toward the exposed end of said smaller diameter portion, said recesses having base surfaces disposed at angles corresponding in degree with the angles of said groove base surfaces but arranged in opposite divergent relation toward said -exposed end of said smaller diameter, portion of the unit.

14. A needle cylinder unit comprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface, said inner element being of tubular form within and projecting axially beyond one end of said outer element, with needle recesses formed in the peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of said unit.

15. .A needle cylinder unit comprising inner and outer separable concentric elements, said outer elementbeing of cylindrical form with needlegrooves in its outer peripheral surface,

said inner elem'ent being of tubular form within and projecting axially beyond one end of said outer"element, with needle recesses formed in the'peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of said unit, and means for securing said elements in said concentric relationship with the recessed end of said inner element extended beyond the one 17. A needle cylinder unitbomprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle groovesin its outer peripheral surface, said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended P tion thereof in alternating relation to said grooves circumferentially' of'said unit, a hollow mandrel within said tubular element with one end projecting axially beyond said extended end of said inner tubular element, and a spray head coaxial withsaid outer elements and said mandrel beyond the exposed end of said mandrel.

18. A needle cylinder unit comprising inner and outer separable concentric elements, said outer elementbeing of cylindrical form with needle grooves in its outer peripheral surface, said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of saidaxially extended portion thereof in alternating relation to said grooves circumferentially of said unit, a hollow mandrel within said tubular element with one end projecting axially beyond said extended end of said inner tubular element, a spray head coaxial with said outer elements and said mandrel beyond the exposed end of said mandrel, an annular flange on the opposite end of said inner element secured to the opposite end of said outer element an annular flange on said mandrel secured to the annular flange of said inner element, and a disc on said spray head secured to p the annular flange of said mandrel for securing a said inner tubular element, and means inter relation to each other.

said inner and outer elements said mandrel and said spray head in concentric relatively extended 19. A needle cylinder unit comprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface. said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of said unit, a hollow mandrel within said tubular element with on end projecting axially beyond said extended end of mediate the/inner surface of said tubular element and the outer surface-cf said mandrel for maintaining said tubular element and said mandrel in radially spaced relation to each other.

20. A needle cylinder unit comprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface, said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of said unit and an annular flange on the opposite end of said inner element overlying and 'separably secured to the opposite end of said outer element.

21. A needle cylinder unitcomprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface, d. inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of saidunit, and an annular flange on the opposite end of said inner element overlying and separably secured to the opposite end of said outer element, with the base surfaces of said needle grooves in said outer element being arranged at convergent angles to the axis of said unit in a direction toward the extended end of said inner element.

22. A needle cylinder unit comprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface, said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of said unit, and an annular flange on the opposite end of said inner element overlying and separably secured to the opposite end of said outer element, with the base surfaces of said needle grooves in said outer element being arranged at convergent angles to the axis of said unit in a direction toward the extended end of said inner element, said extended portion of said inner element being beveled on an angle coextensive with the angle of said needle groove base surfaces.

23. A needle cylinder unit comprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface, said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended portion thereof inalternating relation to said grooves circumferentially of said unit and an annular flange on the opposite end of said inner element overlying and separably secured to the opposite end of said outer element, with the base surfaces of said needle grooves in said outer element being arranged at convergent angles to the axis of said unit in a direction toward the extended end of said inner element, said extended portion of said inner element being beveled on an angle coextensive with the angle of said needle groove base surfaces, and said recesses having base surfaces disposed on oppositely divergent angles of the same degree relative to said unit.

said unit axis as the base surfaces of said needle grooves.

24. A needle cylinder unit comprising inner and outer separable concentric elements, said outer element being of cylindrical form with needle grooves in its outer peripheral surface,

said inner element being of tubular form within and projecting axially beyond one end of said outer element with needle recesses formed in the peripheral surface of said axially extended portion thereof in alternating relation to said grooves circumferentially of said unit and an annular flange on the opposite end of said inner element overlying and separably secured to the opposite end of said outer element, with the base surfaces of said needle grooves in said outer element being arranged at convergent angles to the axis of said unit in a direction toward the extended end of said inner element, said extended portion of said. inner element being beveled on an angle coextensive with the angle of said needle groove base surfaces, and said recesses having base surfaces adjacent the exposed extended end surface of said inner element disposed on oppositely divergent angles of the same degree relative to said unit axis as the base surfaces of said needle grooves and terminating in slots passing completely through the cylindrical wall of said inner element.

25. A needle cylinder unit having an axial bore of predetermined diameter, a main body portion of predetermined outside diameter, and an axially extended reduced portion of lesseroutside diameter than said body portion, said body portion being provided with circumferentially spaced needle grooves having base surfaces arranged on angles relative to the axis of the unit and converging toward said axially extended reduced portion, said reduced portion having a frusto-conical needle-bearing surface at its extreme extended end where the angle of said surface is coextensive with the angles of the groove bases in said outer portion, the transverse plane of the smaller end of the frustrum being coincident with the transverse plane of said extreme end of said axially extended portion, said smaller end of said frustrum having a diameter slightly larger than the diameter of said internal bore, to provide a narrow annular end surface on said unit, whereby the knitting operation will take place within said bore at said extreme end of I WALTER LARKIN. 

